| 摘要 |
<p>The triangular-section girder is of lattice-work construction, for use in gantry and other cranes. The lengthwise members supporting the crab track are of closed hollow section, preferably tubular. Each such hollow member (3) carries a T-section girder (4a) with a vertical flange and a horizontal one (4b). Each girder and its respective member have common transverse external stiffening ribs (6) where cross-members (2c) join onto them. Where the track is directly above the middle girder flange, this can be situated centrally in relation to the hollow member.</p> |
